Naka-ku was a ward in Hamamatsu, Shizuoka, Japan, located in the central part of the city. It encompasses the site of Hamamatsu Castle and Hamamatsu Station, the central business district and a number of high density residential areas. Although its area is the smallest of the seven wards of Hamamatsu, it has the largest population. It is bordered by Higashi-ku, Kita-ku, Minami-ku, and Nishi-ku.